335d DPF Swap

[328 Power 04]

The limp mode is due to a boost leak.. and the lack of regenerations with subsequent clogging of dpf is also due to the boost leaks. This is because the whole system needs to be fully operational in order to do a regen.

It may be too clogged to save, but sometimes, if the car is allowed to do a couple of regens (a special fueling routine that warms up the dpf to burn off the particulates), your current dpf may be recovered. There are even cleaning services available for dpfs.

But the whole problem stems from being in limp mode due to boost leaks.


NOx sensor problems were unfortunately common, because this is a specialty sensor, and a bit fragile. That being said, what codes are there to blame a NOx sensor?

[bmwdirtracer]

https://www.getbmwparts.com/oem-part...60-11618506079
(Full retail $382, from this online dealership $294.) At any shop, you will pay retail.
https://www.getbmwparts.com/oem-part...60-11617799873
(Full retail $330, from this online dealer, $254)

Now, there's another issue here: Personally, I don't like the diagnosis. Sure, these pipes do fail, at their end. More often though, it's because someone had them apart, and didn't clean the oil off, and VERY forcibly reconnect them. They have to hold boost pressure. If the pressure leaks past a pinched o-ring, the car will go into limp mode.

The o-rings are available separately.
https://www.realoem.com/bmw/enUS/sho...diagId=11_4158

I'd want to know how they came by their diagnosis. Did they smoke test the system? Did anyone push / pull like merry hell on the bottom flange of that long pipe on the driver's side? Or check whether that oring is trashed?

You really can't push too hard with the shop, on this; you really need to depend on their integrity, which makes it difficult to know. I'm just going from my own experience, and saying that I have had these hoses come loose, after I've reinstalled them. I've accidentally pinched the orings, and had to go back and find the problem, and replace them.

I've never seen that long charge pipe leak in the middle though.....

I'd get the boost/intake leaks fixed, then clear the codes. The reason your car went into limp mode is very likely a bad o-ring or loose hose end, or both.

- - - Updated - - -

Wow, I did not see Abel's last post until after I posted the above. Still, my thoughts exactly.

[DBimmer335]

Abel - Don't know what codes NOx sensor has been sending however, the Nitric Oxide Sensor (NOx?) has been faulty for the last 2 years while car did not loose any power. Flow BMW in Greensboro, NC had diagnosed it since "Service Engine Soon" fault has been staying on all the time.They has advised to replace Nitric Oxide Senor and EGR Cooler. They said, it's emissions related so I didn't bother to fix it.

The boost leak must be a new thing. Is it possible clogged DPF can loosen the boost hose clamp? I started to notice drop in power couple months ago and within 7-10 days of drop in power bad DPF error message started to pop in the dash. My shop says, the boost hose clamp is loose and can not be tightened and needs to be replaced. I talked with two shops with DPF cleaning. One charges $400 and the other (Hydrogen cleaning) $90 but I was skeptic about this option.

Chris - Thanks for the link for the parts! I don't think boost hose or charge pipe has ever been worked on before so it's strange how boost hose clamp has become loose and charge pipe has gone bad! I will get the details on boost hose and charge pipe tomorrow since car is in the shop today to replace the DPF (used DPF with 59K miles). I have asked the shop manager to somehow tighten the boost hose clamp, if possible (otherwise, I will have spend another $500 to fix it!). As you said, we can not be too pushy with shop guys...

I am wondering, if any member on this board has "home based" repair shop in his garage (in southeast).

[bmwdirtracer]

Personally, I never, ever do side work, except on fellow racer's cars, and even then, hell, I really like my time off. I keep NO tools at home, don't even work on my own cars.

I worked on a Mercedes ML 320 Diesel Turbo today. After changing a couple of fuel lines and serpentine belt, found that one of the intake pipes was badly cracked at a joining area/

German plastic turns to rubber; German rubber turns to plastic. Today I glued some stuff together and made it work for the guy; the part will also be $500 next time it's touched.

[DBimmer335]

Bad News!! I think, I am going through a bad spell or worst luck as far my 335d is concerned. Yesterday, the DPF was replaced and after driving 100-150 miles or so, the DPF fault light came back again! Took the car back to the shop, they tested and read the codes. They still see massive back pressure so the shop manager has predicted the following:
- The replaced DPF is clogged too (kind of unlikely at 59K miles on it)
- CAT might be clogged up
- DPF pressure sensor is bad

The car has hardly any power, kind of still in limp mode. Also, shop manager says, charge pipe/boost hose most likely not causing loss of power because the clamp is very slightly loose and there may not be significant or any leak.

To make the matter worse, out of no where, this evening suddenly my steering wheel froze and burning rubber smell started. I looked under the hood and it was coming from drive belts and I could see the belt was barely moving and smoking.
I have parked the car for now. Don't know what to do....please advise/guide.

[White94RX]

Well, you're definitely going to need a new crank pulley. The rubber of the balancer fails, and then the inside just spins with the crank while the outside part is stationary, and doesn't turn the belts.

[328 Power 04]

What shop is taking care of this car?
I suggest taking it to Markert Motor Works in your area, where they have lots of talent available.


We really need to see codes from the car now.
As long as the system is not allowed to do a regeneration, it will clog it up after some time.
Your car isn't doing a dpf regeneration because of some other issue.
Don't throw away your dpfs as they can be recovered when the car does a regen.

To make sure you don't have leaks, visual inspection is not enough.
It needs to be pressure tested with a smoke machine.
If the ecu notices a boost deviation, it will limp on you and refuse to do a dpf regen.
But of course there may be so many other things.



I helped a semi-local with the same engine, chasing limp modes and all...
I had to log / view all the sensor data and evaluate if it made sense or not.
For example, intake air temp of -47 deg C didn't make sense; atmospheric pressure of 300mbar didn't make sense.
2 bad sensors on that one. I don't know the history, but it was passed from mechanic to mechanic who just guessed and threw the wrong parts at it.
The worst part is that I drove 75 miles to the car to find that out.

[DBimmer335]

My has been worked at BIMMERS. So far their diagnosis and repairs have been accurate however, I am not sure if things are going in the right direction with DPF issue. There is a good possibility, we might have thrown away a good working DPF even though it had 140K miles on it. I wonder why Bimmers is not doing the smoke test as 328 Power 04 and other experts here suggested. When the car is back on the road after the pulley job then I will talk with MMW guys as per your advice. Hope, they will diagnose more accurately.

On a quick note, my shop had tested the ambient pressure and they saw correct readings so they strongly believe, DPF pressure sensor is not the likely culprit.

[bmwdirtracer]

I second Abel's warning about needing a smoke test. There's no good in chasing boost and other gremlins until you're positive that the intake system is perfectly intact.

I know many techs who will not ask for a "second opinion". In fact, I had such a discussion with a LandRover specialist today, who happened to be working on a BMW.....for several days, before he diagnosed the exact same culprit I had diagnosed two weeks prior. I asked him why he didn't come talk to me....as I would talk to him, if I were dealing with a LandRover. He told me that he never asks, because he can't learn that way.

My point is this: Maybe your tech at "Bimmers" is good, maybe he's not.. But, in my opinion, he didn't ascertain the basics, before recommending very expensive parts. I really try hard to TEST first , ask relevant questions and research next....and THEN throw expensive parts.

I also recommend Dave Markert's place, though I've never met the man....his reputation precedes him.

EDIT: Of course, you will need the crank pulley which White 94 RX suggests.

[dworthy]

+3 for the smoke test.

You have to get to a baseline before you can start ruling things out. Right now it has a known charge pipe issue, and when you have a loose clamp, it will leak. So the MAF is saying one thing and the MAP is saying another. Engine is going into limp mode to protect itself.

I know many techs who will not ask for a "second opinion". In fact, I had such a discussion with a LandRover specialist today, who happened to be working on a BMW.....for several days, before he diagnosed the exact same culprit I had diagnosed two weeks prior. I asked him why he didn't come talk to me....as I would talk to him, if I were dealing with a LandRover. He told me that he never asks, because he can't learn that way.

Chris, in my business we call that ignorance. Not asking for help is wasting time, company money, and the customers time.

[DBimmer335]

Thanks Abel, Jim and Darin for the insightful suggestions. I am planning to visit Markert's shop in coming days and have him address the DPF/Limp issue after I get crank pulley replaced. I spent, $800 ($200 on part + $570 on labor) on replacing the DPF but no avail.

Also, I had noticed after the DPF swap, the car was making a weird "hissing" sound during acceleration and it had just a smidge of power for half a day before going back in the total limp mode.

[bmwdirtracer]

That's a very good indication of an intake system leak.

Who is "Jim"?

[DBimmer335]

My bad! I meant you, CHRIS!LOL. I don't know why I typed Jim, can't think straight these days....335d is driving me nuts

[bmwdirtracer]

Just so you know -- You can actually buy a decent smoke machine now, for less than $150, on EBay. It's Chinese, of course (my American RedLine machine cost me $900 ten years ago). But the price makes the EBay one incredibly attractive, especially considering that a single smoke test at a pro shop might cost you $100!

God! They keep getting CHEAPER every time I look!

https://www.ebay.com/itm/Autool-SDT-...uhl:rk:17:pf:0

If you buy your own smoke machine, always make sure to use it AFTER any MAF sensor! MAF sensors HATE oil, and smoke machines use baby oil.

[DBimmer335]

Thanks, Chris! I will give it a thought. Btw, I just noticed a new thread on DPF where a 2011 335d with only 43000 miles has clogged DPF issue! I was wondering if DPF can clog at so low miles on it!

[bmwdirtracer]

I am not a diesel specialist, but I will say that a car that gets driven only 500 miles a month for eight years probably never gets warmed up, and certainly never burns out the DPF.